This is a rather simple perl module for dealing with time intervals.
Among other things,
this module can tell you the number of hours,
minutes,
and seconds elapsed between two dates.

NOTE: this module does not handle resolutions < 1 second.
Please see the Time::HiRes module for high resolution time operations.
This module will round fractional second values to the nearest whole number.

this argument controls how the interval will be returned. If not defined, the inerval will be returned as a hash reference containing the number of days, hourse, minutes and seconds between the two dates. If the following values are specified the interval will be returned as a string:

given a set of time intervals (start and end time pairs), this method will return the minimum set based on overlapping time spans. That is, this method will return a list of unique contiguous time intervals from the given list. As with the other methods in this package, time strings may be submitted in any of the formats supported by Date::Parse. Data is returned as it was passed in, as a reference to an array of array references (see below).

coalesce takes only one argument, an array reference. The reference should be to an array of array references, each of which contains a start and an end time. For a quick example, take a look at the SYNOPSIS section.